#region Copyright notice and license

// Copyright 2019 The gRPC Authors. Modified by AElfProject.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#endregion

using System.Collections.Generic;
using System.Collections.ObjectModel;
using AElf.CSharp.Core;
using Google.Protobuf.Reflection;

namespace AElf.Runtime.CSharp;

internal static class ServerServiceDefinitionExtensions
{
    /// <summary>
    ///     Maps methods from <c>ServerServiceDefinition</c> to server call handlers.
    /// </summary>
    internal static ReadOnlyDictionary<string, IServerCallHandler> GetCallHandlers(
        this ServerServiceDefinition serviceDefinition)
    {
        var binder = new DefaultServiceBinder();
        serviceDefinition.BindService(binder);
        return binder.GetCallHandlers();
    }

    internal static IReadOnlyList<ServiceDescriptor> GetDescriptors(this ServerServiceDefinition serviceDefinition)
    {
        var binder = new DefaultServiceBinder();
        serviceDefinition.BindService(binder);
        return binder.GetDescriptors();
    }

    /// <summary>
    ///     Helper for converting <c>ServerServiceDefinition</c> to server call handlers.
    /// </summary>
    private class DefaultServiceBinder : ServiceBinderBase
    {
        private readonly Dictionary<string, IServerCallHandler> callHandlers = new();
        private readonly List<ServiceDescriptor> descriptors = new();

        internal ReadOnlyDictionary<string, IServerCallHandler> GetCallHandlers()
        {
            return new ReadOnlyDictionary<string, IServerCallHandler>(callHandlers);
        }

        internal IReadOnlyList<ServiceDescriptor> GetDescriptors()
        {
            return descriptors.AsReadOnly();
        }

        public override void AddMethod<TRequest, TResponse>(
            Method<TRequest, TResponse> method,
            UnaryServerMethod<TRequest, TResponse> handler)
        {
            callHandlers.Add(method.Name, ServerCalls.UnaryCall(method, handler));
        }

        public override void AddDescriptor(ServiceDescriptor descriptor)
        {
            descriptors.Add(descriptor);
        }
    }
}